Frailty in Medicare Advantage Beneficiaries and Traditional Medicare Beneficiaries

Key Points Question Do Medicare Advantage beneficiaries have lower levels of frailty and slower decline than traditional fee-for-service Medicare beneficiaries? Findings In this nationally representative cohort study of 7063 community-dwelling individuals aged 65 years and older, compared with traditional fee-for-service Medicare beneficiaries, Medicare Advantage beneficiaries had higher levels of frailty at baseline but similar levels of frailty change over 1 year. Meaning These findings suggest that enrollment in Medicare Advantage plans is not associated with altered frailty trajectories compared with Traditional Medicare, and more work is needed to better understand the health services needs of older adults with frailty.


Introduction
In recent years, Medicare Advantage (MA) has become increasingly common, with 29.5 million enrollees, representing 51% of all Medicare beneficiaries in 2023. 1,2MA plans typically offer lower premiums and cover some additional benefits, such as vision screening and dental coverage, but enrollees face a more limited network of practitioners compared with traditional fee-for-service Medicare (TM). 3 Moreover, MA beneficiaries differ from TM beneficiaries across both health and socioeconomic status, 4 with contemporary MA enrollees more likely to be Black or Hispanic, to have lower income, and to be dually eligible for Medicaid. 5,6In particular, MA has special needs plans (SNPs) for dually eligible beneficiaries, who often have a higher burden of chronic or disabling conditions.
Frailty is a crucial measure of health for older adults, representing a vulnerable state of diminished physiologic reserve. 7,80][11] Frailty progression may be partially mitigated by social integration and participation, 12 which could be better supported with the additional services offered by MA plans.Although previous work 5 has demonstrated that beneficiaries with disabilities are less likely to enroll in MA, the extent to which frailty and frailty trajectories may differ between MA and TM beneficiaries has not been examined previously.Here, we conducted a retrospective study to determine the extent to which (1) frailty and related characteristics differ between MA and TM beneficiaries, and (2) frailty and markers of physical function differ between MA and TM changes over 1 year.

Methods
In this cohort study, we analyzed 2015 to 2016 data from the National Health and Aging Trends Study

Statistical Analysis
We compared sociodemographic and frailty measures at baseline between MA and TM beneficiaries using χ 2 tests for categorical variables and an adjusted Wald test for continuous variables, with significance set at 2-sided P < .05.Linear regression was used to compare the changes (follow-up minus baseline) in gait speed and FI, FFP, and SPPB scores between MA and TM enrollees, adjusting for age, sex, dual eligibility for Medicare and Medicaid, cohabitation status, income category, and baseline scores (ie, change in FI adjusted for baseline FI).Logistic regression was used to assess the association of MA status with the likelihood of experiencing a decline by MCID in each outcome measure in 1 year.We repeated analyses in those with frailty (defined as FI Ն0.25) and with possible or probable dementia.All analyses were conducted using Stata statistical software version 15.0 (StataCorp), accounting for the complex sampling design, and were weighted to reflect national estimates. 23Analyses were conducted from August 2023 to March 2024.Analyses in prespecified subpopulations of persons with frailty (Table 3) and those with cognitive impairment (Table 4) yielded similar results.There were no significant differences between MA and TM populations in changes in FI, FFP, or SPPB score, gait speed, or odds of having an MCID in any of these measures.When analyses were repeated requiring 12 months of enrollment, results

Characteristics of MA and TM Enrollees
were similar, with no changes in 1-year frailty trajectories between the 2 populations.

Discussion
In this nationally representative cohort study of Medicare beneficiaries in 2015, we compared frailty characteristics between MA and TM beneficiaries using validated frailty measures.MA beneficiaries had a higher burden of frailty by 2 validated frailty measures: FI and FFP.However, changes in frailty measures were similar in the 2 populations among beneficiaries after 1 year.
Historically, MA plans were observed to attract healthier individuals, perhaps owing to favorable selection by those who would benefit from wellness plans or were attracted to lower premiums. 24a Change in scores are calculated as the difference from 2015 to 2016 survey measurements.For frailty scores, higher scores are worse.For SPPB and gait speed, higher scores are better.Models are adjusted for age, sex, dual eligibility for Medicare and Medicaid, cohabitation status (alone vs partner vs partner and others vs others), categorical income, and baseline status (ie, change in FI adjusted for baseline FI).
b Minimum clinically important differences are 0.03 for FI, 1 for SPPB score, and 0.1 m/s for gait speed.
c Data are odds ratio (95% CI).However in recent years, MA enrollment has grown, primarily as a result of TM beneficiaries switching to MA, 25 rather than new enrollments, and many of those who switch are not necessarily in better health.In particular, beneficiaries who switched were more likely than new enrollees to have disabilities, possibly reflecting a need for the additional services provided. 26Beneficiaries may be drawn to potentially lower out-of-pocket costs or additional benefits offered by MA plans, such as vision, dental, or wellness plans. 27Other known characteristics associated with switching include dual-eligibility 28 and racial or ethnic minority status, which we also found in MA beneficiaries.This suggests that the more comprehensive coverage of MA plans may be more appealing for more relatively vulnerable populations.Interestingly, despite these additional services, changes in frailty, physical performance measures, and health outcomes did not significantly differ between MA and TM populations in our study.Our study did not allow for specific examination of what supportive services were available or used at the beneficiary levels, which may vary highly from plan to plan.
Thus, it remains unclear whether availability and usage of specific services may alter frailty trajectories in vulnerable populations.
Our study is observational in nature and cannot fully capture the complex reasons and motivations behind beneficiaries' selection of insurance plans.For example, it is possible that MA beneficiaries had experienced worsening frailty before choosing MA plans, and that MA insurance may attenuate their overall health decline, thereby making their trajectories more comparable to those of TM beneficiaries.
Although previous research suggests that beneficiaries with worsening function tend to switch into TM plans, this pattern may not hold for all beneficiaries, especially those who may benefit from SNPs or enhance care management and coordination.Further investigations, particularly around changes in frailty following switches in insurance plans, are needed to illuminate this issue.
Within the 1-year follow-up period, we excluded those who died or were lost to follow-up in 2016, which may have led to selection bias.Previous literature 29 has established that mortality rates, when adjusted for age, sex, and dual-eligible status, are typically lower among MA beneficiaries.
Although those who were lost to follow-up had a higher degree of frailty than those who remained in the cohort, loss to follow-up was not different by insurance status (eTable in Supplement 1).A sensitivity analysis conservatively assuming that all who were lost to follow-up experienced worsening frailty did not yield appreciably different estimates.
With the increasing role of MA plans in providing care for frail older adults, future health services research restricted to TM populations may not adequately represent the diverse, vulnerable aging population.Previous work 4 has established that a higher proportion of low-income beneficiaries and those from racial and ethnic minoritized groups are enrolled in MA.Our study also examined social participation measures, which may be a critical modifiable factor associated with improved health outcomes. 30Interestingly, we found that those enrolled in MA were more likely to live with others but less likely to go out for enjoyment, possibly reflecting more limited life-space mobility, 31 which is associated with future health care utilization. 32Although MA plans, specifically those for dualeligible individuals, may cover some supplemental benefits such as meal delivery and nonmedical transportation, 33 whether these can support or improve social participation remains unclear.
Examples of conditions targeted by SNPs include congestive heart failure and diabetes, which were also common in our study cohort.Prior work 34 has found that MA beneficiaries not in SNPs are similar to TM beneficiaries in terms of demographics and overall chronic conditions.It is possible that MA beneficiaries in SNPs tend to have a higher degree of frailty, which is reflected in the higher prevalence of moderate-to-severe frailty seen in the MA population.However, not all MA beneficiaries with a chronic condition are necessarily enrolled in a chronic condition SNP, and we could not directly identify whether beneficiaries were specifically enrolled in these SNPs.Although at present there are SNPs specific for dementia, there was only 1 dementia SNP offered in 2014. 35Thus, in all likelihood, those with dementia enrolled in MA were not in a dementia SNP and may not have necessarily benefited from any dementia-specific services.Thus, our findings that MA beneficiaries were more likely to have possible or probable dementia are somewhat surprising, suggesting that those with cognitive impairments may preferentially seek MA plans regardless of SNPs.

JAMA Network Open | Health Policy
Frailty in Medicare Advantage and Traditional Medicare Beneficiaries

(
NHATS), a nationally representative survey of Medicare beneficiaries linked to Medicare claims data.Surveys are conducted annually in participants' homes, including medical history, socioeconomic status, cognitive and physical assessments, and functional status.For baseline comparisons of frailty status between MA and TM enrollees, we included all 7070 living community-dwelling Medicare beneficiaries in the 2015 survey, excluding 3 respondents with insufficient data to classify insurance status and 4 with insufficient data to calculate frailty.To analyze the change in frailty over time, we further excluded 305 who died, 723 who were lost to follow-up by the 2016 survey, and 27 who had insufficient data to calculate frailty (Figure).

Table 1 .
Characteristics of Medicare Advantage and Traditional Medicare Enrollees JAMA Network Open.2024;7(8):e2431067.doi:10.1001/jamanetworkopen.2024.31067(Reprinted) August 30, 2024 5/11 Downloaded from jamanetwork.comby guest on 09/05/2024 After multivariable adjustment, MA was not associated with significant changes in FI, FFP, or SPPB score or gait speed.In adjusted logistic models, MA was not associated with the odds of having an MCID in FI, FFP, or SPPB score and gait speed, as well as falls and hospitalizations.

Table 1 .
Characteristics of Medicare Advantage and Traditional Medicare Enrollees (continued) a Percentages are weighted to reflect national estimates.bOther race includes American Indian, Alaska Native, Asian, Native Hawaiian, and Pacific Islander.Those who answered more than 1 primary, do not know or refused to answer, or missing were treated as missing.

Table 2 .
One-Year Change in Frailty and Related Characteristics Between Traditional Medicare and Medicare Advantage Beneficiaries b Minimum clinically important differences are 0.03 for FI, 1 for SPPB, and 0.1 m/s for gait speed.cData are odds ratio (95% CI).

Table 3 .
One-Year Change in Frailty and Related Characteristics Between Traditional Medicare and Medicare Advantage Beneficiaries With Frailty cAbbreviations: FFP, Fried Frailty Phenotype; FI, frailty index; SPPB, Short Physical Performance Battery.

Table 4 .
One-Year Change in Frailty and Related Characteristics Between Traditional Medicare and Medicare Advantage Beneficiaries With Cognitive Impairment c Data are odds ratio (95% CI).